Module handshake 

Client handshake steps as pure Read/Write byte functions (identity tuples, no Verbs) — un-gated so the transcript goldens run everywhere.

Functions

read_ack

Final step: the peer’s one-byte ready ack, which must be STATUS_OK.

read_rw_server_params

RW-blade dialect (KV overflow / snapshots): read the peer’s [u8 n] echo (must equal the negotiated want; deliberately NOT bounded to 8 — the RO dialect’s 1..=8 bound is its own, and unifying validation would change accepted wire inputs) followed by n CacheServerParams.

write_client_params

Reply with our rail count (again — wire format) + each rail’s QP identity.

write_n_rails

Step 1: tell the peer how many rails we want to stripe across.